After a tumultuous first-ever open enrollment period under federal health reforms, Oregon health insurers are bracing for round two.

Rate filings by carriers this week show that barely a month after seizing a commanding share of Oregon's individual health insurance market in this year's enrollment period, Moda Health is asking for an average 12.5 rate increase in 2015.

Meanwhile, many competitors are seeking to drop their premiums next year to get closer to Moda's 2014 premiums. Providence Health Plan is seeking an average 16.9 percent average rate decrease, while Oregon's Health CO-OP is going further with a decrease of 21 percent overall.

"It's a very competitive market," said the CO-OP's CEO, Ralph Prows. "There were lessons learned this past year that I think everyone is applying."

The rate filings apply only to those who purchase their own insurance and are not covered by Medicare or through an employer. The filings are only preliminary, and must win state approval following public hearings.

Not only that, but actual changes to individuals' plans and premiums will vary widely based on factors including age and geography, making the carriers' average rate change deceiving, insurance representatives say.

Still, the proposals provide a broad-brush first look at year two of the Patient Protection and Affordable Care Act. And what's clear is that the broad range of individual-market premiums submitted this year is tightening up.

Moda Health last year proposed bargain basement premiums for some of its plans that were so low some felt the company may have underpriced its offerings.

A 40-year-old person in the Portland area paid $162 a month for a bronze-level Moda plan in 2014, compared to $188 for the companies' nearest competitor.

The firm roughly doubled its market share of individual plans, covering 82,000 people or more than 40 percent of the market.

Now Moda officials say the firm is raising rates largely due to a decrease in federal subsidies for individual health insurers to offset rate hikes under the Patient Protection and Affordable Care Act.

"That's the big one," said Robert Gootee, Moda's President and CEO. "The other big one is medical (inflation)."

He said while his company was looking strictly at bottom-line numbers, other insurers are likely looking to build market share

"People that want to compete in this market are going to be coming down closer to us," he said.

Dawn Bonder, president and CEO for Health Republic, already offered premiums clustered in the tier immediately above Moda. Her firm is asking for a miniscule average rate decrease of .6 percent despite the decrease in federal subsidies thanks to some plan adjustments and other changes, she said. "We're pricing for sustainability."

Gary Walker, a spokesman for Providence Health Plan, said the firm's requested decrease is based on anticipated savings as well as "our desire to provide more people with access to health care services."

Kaiser Foundation Health Plan of the Northwest is boosting its average premium barely based on status quo projections, according to its filing.

Regence BlueCross BlueShield of Oregon, which was already priced above many insurers, requested an overall rate hike of about 5 percent, though details vary dramatically between plans. A spokeswoman for the firm, Laura Jones, said Regence's premiums were based on "what our actuaries predict our actual costs will be."

Over the next several days, actuaries for the Oregon Insurance Division will be poring through filings, looking for errors and omissions. Then rate requests will go through public hearings before the division approves premiums.

Jesse O'Brien of The OSPIRG Foundation said that considering the "amazing variation" between carriers' proposals, "it's more important than ever that these rates be scrutinized closely."

Consumers don't need to worry about signing up for 2015 policies until Nov. 15 when the next open enrollment begins. To read the detailed filings, go here and click on SERFF.